This invention relates to the manufacture of rod-like articles, and in particular to such articles useful in the manufacture of cigarettes.
Cigarettes are rod-like articles including a circumscribing wrap such as paper enveloping strands of smokable material such as tobacco. Particularly popular cigarettes include a tube-like circumscribing wrap containing strands of a blend of various tobaccos thereby forming a rod having a circular cross section. Such rods are conventionally referred to as "tobacco rods." Typical cigarettes are manufactured from tobacco rods having lengths ranging from about 55 mm to about 85 mm, and circumferences ranging from about 19 mm to about 27 mm.
Tobacco rods are manufactured using commercially available rod making units. Generally, strands of a blend of tobacco (i.e., tobacco filler) is continuously fed onto a moving web of cigarette wrapping material from a bobbin. The moving web is transported through a rod-forming unit by a garniture conveyer belt. Within the rod-forming unit, the wrapping material is positioned so as to envelope the tobacco filler, and the wrapping material is secured into a tube-like shape by applying an adhesive to the lap zone thereof. The continuous rod so provided is transported from the rod-forming unit to a subdividing means where the continuous rod is cut at the desired lengths to provide a plurality of rods. The plurality of tobacco rods are subjected to further processing steps in order to provide the final cigarette product.
During the processing and transport of tobacco filler to the rod-forming unit, certain undesirable impurities can come into contact therewith. For example, foreign matter such as metal particulates can be present in the tobacco filler, and consequently can be incorporated into the resulting tobacco rods. Having metal impurities present in tobacco filler is highly undesirable in that there is provided added difficulty in manufacturing consistently high quality cigarette rods.
It would be highly desirable to provide an efficient and effective process for separating tobacco rods having particulate metallic impurities therein from the desirable, high quality tobacco rods essentially free of particulate metallic impurities.